We propose to continue producing and characterizing monoclonal antibodies to human spermatozoa, and isolating antigens from the relevant monoclonal antibodies. Such antigens have possible uses as an immunocontraceptive vaccine, immunodiagnosis of infertility, and the study of various fertilization and ontogenic processes. Our goal is to establish a bank of hybridoma cell lines specific to the cell surface of germ cells and relevant to the isolation of specific antigens. We will characterize monoclonal antibodies: (1) immunohistologically, to localize and follow the fate of individual molecular species on sperm; (2) biochemically, to determine the molecular identities of the antigenic molecules; (3) in functional assays--such as (a) sperm immobilization, (b) agglutination, (c) in vitro cervical mucus penetration, and (d) hamster ovum penetration--to determine if they affect the ability of sperm to penetrate eggs; (4) to determine their effects on fertility in in vitro and in vivo systems; and (5) with affinity chromatography, to isolate the specific antigens involved and then to characterize them and check their utility for immunodiagnosis and contraception. We will use the monoclonal antibodies: (1) to compare sperm iso- and autoantigens in serum and seminal plasma from infertility patients and vasectomized men and (2) to artificially inseminate mice and rabbits by means of sperm treated with monoclonal antibodies which react to the sperm of these species or to immunize them, passively or actively, to more thoroughly evaluate the role of antisperm antibodies in infertility. Sperm-specific monoclonal antibodies will enable us and others to define the mechanisms underlying fertility. Thus, we shall build a foundation for new approaches in the diagnosis of infertility, treatment of infertile patients, and development of better immunocontraceptives.